UPDATE: Rare August Thunderstorm Rocks San Francisco Bay Area; Lightning Strikes Spark Widespread Wildfires – CBS San Francisco

SAN FRANCISCO (CBS SF) — A rare August severe storm system rolled through the San Francisco Bay Area early Sunday, packing a combination of dry lightning and high winds that triggered wildfires throughout the region.

The National Weather Service on Sunday extended a red flag fire warning for the entire Bay Area until 11 a.m. Monday morning.

“Any lightning strikes will likely lead to new fire starts given the current heat wave,” forecasters warned. “A secondary pulse of moisture and instability arrives later Sunday into early Monday.”

Bay Area firefighters were busy as the storm moved through.

PG&E webcams captured images of a rather large wildfire in the Santa Cruz Mountains at around 5:30 a.m. Additional strike teams were rushed to the area by 6 a.m. with high winds spreading the fire and threatening structures. Air support was requested to begin at daylight.

Marin County Fire reported at 4:15 a.m. that its crews were “responding to numerous lightning strikes in the area of King Mountain and San Geronimo and throughout the county. No current evacuation orders or warnings in place.”

Downed PG&E lines had triggered power outages from neighborhoods in San Rafael all the way into western Marin County. Fire crews were able to quickly contained a vegetation fire burning on the ridges on the Zig Zag Trail.

Smoke was also seen from a small fire on Mt. Tam.

Calfire sent crews to a lightning cause fire in the area of 20730 Brush Road in Redwood Estates Area that initially threatened homes and forced some evacuations before forward progress was halted around 4 a.m. Another wildfire erupted near Highway 1 north of Davenport and had grown to 3 acres.

Crews were also dispatched to battle a growing vegetation fire in the area of 5201 Arroyo Road in Livermore.

By 6:35 a.m, Calfire reported that firefighters were aggressively attacking the 2-alarm Arroyo fire, being fueled an Eucalyptus grove, and holding it at 50 acres and with 50% containment.

Meanwhile, the Sonoma County Sheriff’s Department alerted that “law Enforcement and fire personnel are receiving multiple calls for service involving downed trees and powerlines. A few spot fires within the county have also been reported.”

In Contra Costa County, there were several fires in the area of Morgan Territory and Marsh Creek roads near Mt. Diablo State Park. Officials said the fires were putting out a lot of smoke. Units from Cal Fire, the Contra Costa County Fire Protection
District and San Ramon Valley Fire Protection District were among those who responded.

In Santa Clara County, fire officials said downed power lines sparked a fire in an unincorporated area on Brush Road near state Highway 17 that started just before 3 a.m. and forced the evacuation of 20 residents. It was contained by 6 a.m. after burning a little more than an acre.

In the South Bay near Salinas, firefighters were battling a growing 10-acre blaze in Pine Canyon.

The intensity of the storm system triggered a severe thunderstorm warning for the entire San Francisco Bay Area as local residents were awakened by the roar of thunder. The warning for Contra Costa, Alameda, Napa, San Francisco and Santa Clara counties was extended until 8 a.m.

The weather service also issued a special marine warning for the waters of San Francisco, San Pablo, Suisun Bays and the west Delta.

At 5:30 a.m., weather service radar was showing that “frequent lightning still persists around the BayArea and the CentralCoast, as new storms are firing over the ocean and moving toward the San Mateo Peninsula.”

Bay Area residents took to social media with remarkable images of the storm.

The National Weather Service said wind gusts generated by the fast-moving system were being clocked as high as 66 mph. NWS Forecasters reported gusts of 66 mph on Atlas Peak, 65 mph at Hawkeye, 48 mph at St. St Helena, 45 mph on Mt. Tam and 42 mph on Mt Diablo.

“The cluster of severe thunderstorms are generating extremely strong erratic wind gusts which can cause downed trees, power lines, and other structural damage as well as difficulty driving,” NWS forecasters tweeted.

They also posted on Twitter a photo of a massive, rare “roll cloud” along the Santa Cruz Coast shortly before 3 a.m.

The storm came as the region has been locked into a sweltering heat wave. Record temperatures again fell across the region on Saturday and the early morning rains would only provide a brief respite. Forecasters predicted another four days of temperatures in the triple digits in the inland areas.